我已经在这里尝试了几种答案，并且我认为我有一个可以每次都起作用并且还可以管理权限的解决方案。
它基于LEO的巧妙解决方案。这篇文章应该包含完成这项工作所需的所有代码，并且应该适用于任何手机和Android版本;）
为了能够从SD卡中选取文件，您需要在清单中添加以下文件：
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
常数：
private static final int PICK_IMAGE = 456; // Whatever number you like
public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL = 28528; // Whatever number you like
public static final String FILE_TEMP_NAME = "temp_image"; // Whatever file name you like
检查权限并在可能的情况下启动launchImagePick
if (ContextCompat.checkSelfPermission(getThis(),
Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(getThis(),
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_READ_EXTERNAL);
}
else {
launchImagePick();
}
权限回应
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull
String permissions[],
@NonNull
int[] grantResults) {
if (manageReadExternalPermissionResponse(this, requestCode, grantResults)) {
launchImagePick();
}
}
管理权限响应
public static boolean manageReadExternalPermissionResponse(final Activity activity, int requestCode, int[] grantResults) {
if (requestCode == MY_PERMISSIONS_REQUEST_READ_EXTERNAL) {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission was granted, yay! Do the
// contacts-related task you need to do.
return true;
} else if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_DENIED) {
boolean showRationale = ActivityCompat.shouldShowRequestPermissionRationale(activity,
Manifest.permission.READ_EXTERNAL_STORAGE);
if (!showRationale) {
// The user also CHECKED "never ask again".
// You can either enable some fall back,
// disable features of your app
// or open another dialog explaining
// again the permission and directing to
// the app setting.
} else {
// The user did NOT check "never ask again".
// This is a good place to explain the user
// why you need the permission and ask if he/she wants
// to accept it (the rationale).
}
} else {
// Permission denied, boo! Disable the
// functionality that depends on this permission.
}
}
return false;
}
启动图像选择
private void launchImagePick() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
startActivityForResult(intent, PICK_IMAGE);
// see onActivityResult
}
管理图像选择响应
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == PICK_IMAGE) {
if (resultCode == Activity.RESULT_OK) {
if (data != null && data.getData() != null) {
try {
InputStream inputStream = getContentResolver().openInputStream(data.getData())
if (inputStream != null) {
// No special persmission needed to store the file like that
FileOutputStream fos = openFileOutput(FILE_TEMP_NAME, Context.MODE_PRIVATE);
final int BUFFER_SIZE = 1 << 10 << 3; // 8 KiB buffer
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) > -1) {
fos.write(buffer, 0, bytesRead);
}
inputStream.close();
fos.close();
File tempImageFile = new File(getFilesDir()+"/"+FILE_TEMP_NAME);
// Do whatever you want with the File
// Delete when not needed anymore
deleteFile(FILE_TEMP_NAME);
}
}
catch (Exception e) {
e.printStackTrace();
}
} else {
// Error display
}
} else {
// The user did not select any image
}
}
}
那是所有人。这对我所有的电话都有效。
Uri应该可以通过开启为流ContentResolver。我一直对应用程序感到紧张，这些应用程序假设content://Uri代表文件的a总是可以转换为File。